Three-dimensional MEMS devices have been an area of interest for a number of years. The off-substrate (also referred to as out-of-plane) dimensions of MEMS devices have typically been relatively small, with most micromachining processes only able to fabricate low aspect ratio structures—i.e. structures with relatively small off-substrate dimensions relative to their on-substrate (in-plane) dimensions.
Newer micromachining fabrication technologies, such as deep reactive ion etching (DRIE) have produced higher aspect ratio structures in silicon. Most DRIE processes are limited to a single structural thickness and offer limiting off-substrate functionality. To overcome the shortcomings of planar surface micromachining technology, assembly mechanisms have been developed to take thin on-substrate structures and manipulate particular components to provide off-substrate structures. This form of manipulating on-substrate components to provide out-of plane structures has been performed using integrated on-chip actuators or pick-and-place external robotic systems. Micromachined hinges have also been developed to provide out-of-plane structures by permitting particular components to rotate out of the substrate plane. A number of compliant mechanisms have also been introduced to permit serial assembly of MEMS structures with a single push. Examples of prior art processes for fabricating off-substrate MEMS components include:    Reid J R, Bright V M and Butler J T 1998 Automated assembly of flip-up micromirrors Sensors Actuators A 66 292-8;    Tien N C, Solgaard O, Kiang M-H, Daneman M, Lau K Y and Muller R S 1996 Surface-micromachined mirrors for laser-beam positioning Sensors Actuators A 52 76-80;    Tsui K, Geisberger A A, Ellis M and Skidmore G D 2004 Micromachined end-effector and techniques for directed MEMS assembly J. Micromech. Microeng. 14 542-9;    Kaajakari V and Lal A 2003 Thermokinetic actuation for batch assembly of microscale hinged structures J. Microelectromech. Syst. 12 425-32;    Lai K W C, Hui A P and Li W J 2002 Non-contact batch micro-assembly by centrifugal force 15th IEEE Int. Conf Micro Electro Mechanical Systems pp 184-7;    Johnstone R W, Sameoto D and Parameswaran M 2006 Non-uniform residual stresses for parallel assembly of out-of-plane surface-micromachined structures J. Micromech. Microeng. 16 N17-22;    Pister K S J, Judy M W, Burgett S R and Fearing R S 1992 Microfabricated hinges Sensors Actuators A 33 249-56;    Johnstone R W, Ma A H, Sameoto D, Parameswaran M and Leung A M 2008 Buckled cantilevers for out-of-plane platforms J. Micromech. Microeng. 18 045024;    Tsang S H, Sameoto D, Foulds I G, Johnstone R W and Parameswaran M 2007 Automated assembly of hingeless 90° out-of-plane microstructures J. Micromech. Microeng. 17 1314-25.
There is a general desire to provide self-assembling MEMS structures with out-of-plane components.
Typical wireless devices and communication networks require antennas to send and receive information via electromagnetic waves. For miniaturized devices and for other applications (e.g. System-on-Chip (SoC) and System-in-Package (SiP) applications), it is desired to integrate antennas onto the same chip, into the same package or at least in close proximity to the chip on which the antenna feeding mechanism and/or other signal/data processing components are implemented.
Conventional on-chip antennas are typically of the in-plane patch-type that extend in the plane of the substrate—see, for example, M. Pons et al., “Study of on-chip integrated antennas using standard silicon technology for short distance communications,” 2005 European Microwave Conference, October 2005 and E. Ojefors et al., “Micromachined Loop Antennas on Low Resistivity Silicon Substrates: IEEE Transactions on Antennas and Propagation, Vol. 54, No. 12, pp. 3593-3601, December 2006. However, in CMOS, GaAs and other technologies, the substrate on which antenna feeding mechanism and/or other signal/data processing components (e.g. analog-to-digital converted, amplifiers and the like) are implemented can be lossy (i.e. relatively conductive) and can result in reduced antenna efficiency. Such conductivity may be required in CMOS technology to prevent latch-up issues, for example. Because the substrate is lossy, in-plane patch-type antennas suffer from low efficiency. which in-turn impact the range and data-rate of the communication system.
There is a general desire to distance at least portions of antennas from the substrate to avoid unnecessary losses in antenna efficiency. There are corresponding desires to provide antenna design flexibility which allow control over antenna parameters, such as the length, elevation, azimuthal angle and profile shape of the antenna.
The reader should appreciate that in the illustrative drawings presented herewith lines and/or shading may be provided to delineate features for clarity even though such delineation may not actually be present in corresponding structures.